Willey et al.; A comparison of circle hook and J hook performance 
371 
Foul Jaw Throat Gut 
Hook location 
Figure 1 
Hook locations (n=622) observed, 2012-2014, during a study of 
interactions of sharks with circle and J hooks in the recreational 
shark fishery off Maryland. Data for 2 landed sharks were not 
included in this figure because either a hook location was not 
recorded or the shark had become entangled in the line and a 
hooking event did not occur. A location at throat or gut was con- 
sidered a deep hooking. 
Bite Lost Captured 
Hooking outcome 
Figure 2 
Outcomes of hooking events (n=781) observed during 2012-2014 
as part of a study of interactions of sharks with circle and J 
hooks in the recreational shark fishery off Maryland, classified 
into 3 categories: 1) bite, when a shark took the bait but was not 
hooked; 2) lost, when a hooked shark became unhooked before 
the mate could grab the leader; and 3) captured, when a shark 
was fully played to the boat and the mate grabbed the leader. 
could not confirm that it was a shark bite. A lost clas- 
sification was defined as the outcome where a hooked 
shark became unhooked before the mate could grab the 
leader. A captured classification was the outcome when 
a shark was fully played to the boat and the mate 
grabbed the leader. Hook location was recorded as jaw, 
throat, gut, or foul (external). Entangled fish were docu- 
mented but excluded from the analysis because they 
were not actually hooked. Deep hooking was 
defined as hooking in the throat or gut. 
Statistical methods 
Trips were identified as nearshore or offshore 
because of differences in species composition 
and tackle requirements. Nearshore trips oc- 
curred in waters within 32.2 km (20 mi) of 
land, and offshore trips took place in waters 
32.2 or more kilometers from land. Most of the 
nearshore fishing occurred within 1.6-9. 7 km 
(1-6 mi) of the beach, and the majority of off- 
shore fishing took place between 32.2 and 48.3 
km (20 and 30 mi) from the beach. 
Data were pooled across years, and the fol- 
lowing tests were performed. Chi-square analy- 
sis was used to determine whether nearshore 
and offshore trip data could be pooled. Hypoth- 
esis tests of proportions were conducted to com- 
pare hooking outcomes and to compare rates of 
deep hooking between hook types. Catch rate 
was defined as the number of sharks captured 
per interaction and calculated as the mean of 
trip values. Student’s Atest was used to com- 
pare catch rates between hook types. 
Results 
Data were collected during 24 offshore and 
180 nearshore trips, and the results of chi- 
square analysis indicated that nearshore and 
offshore data could be pooled for all analyses 
(all P>0.10). During this study, 624 sharks 
representing 10 shark species were captured, 
primarily dusky shark (Carcharhinus obscu- 
rus; n=235), spinner shark {Carcharhinus bre- 
vipinna; n=180), sandbar shark {Carcharhinus 
plumbeus; n=89), and Atlantic sharpnose shark 
{Rhizoprionodon terraenovae; n=70). The other 
species caught were the blue shark {Prionace 
glauca; n=15), blacktip shark {Carcharhinus 
limbatus; ?z=13), tiger shark {Galeocerdo cu- 
vier; n=7), shortfin mako {Isurus oxyrinchus; 
n=7), scalloped hammerhead {Sphyrna lewi- 
ni] n=5), and smooth hammerhead {Sphyrna 
zygaena; n=3). 
There were 438 shark interactions with cir- 
cle hooks and 343 interactions with J hooks. 
Interactions with circle hooks resulted in a 
91% hooking rate of which 95% of sharks were 
hooked in the jaw and only 3% were deep hookings 
(Fig. 1). Circle hooks had an 88% capture rate (Fig. 
2) and a catch rate of 0.9 sharks/hook interaction. For 
J hooks, the hooking rate was 75% of which 82% of 
sharks were hooked in the jaw and 6% deep hookings. 
The capture rate was 68% and the catch rate was 0.7 
sharks/hook interaction. All differences were significant 
with P<0.01. 
